It is known in the prior art to energize the propulsion equipment of a transit vehicle from a power source, and to provide a regenerative braking operation with a passenger vehicle, as described in an article entitled "Alternative Systems for Rapid Transit Propulsion and Electrical Braking" by B. J. Krings which appeared in the Westinghouse Engineering for March, 1973, at pages 34 to 41.
It is known in the prior art to sense when a vehicle is positioned within a gap in a third rail power supply, and to sense the current supplied to auxiliary devices carried by the vehicle for determining when regenerating current is permitted to go back to the power line as described in U.S. Pat. No. 4,326,154 of R. R. Lewis et al.
It is known in the prior art to provide a direct current motor control apparatus for determining the operational speed of one or more direct current motors, such as traction motors propelling a passenger vehicle along a track, and to utilize solid state switch devices to determine one of a propulsion or brake mode of operation of the motor control apparatus as disclosed in U.S. Pat. No. 4,284,930 of T. C. Matty.